1. Field of the Invention
The present invention relates to an optical pickup apparatus used for recording to and reproducing from an optical disk, a method of assembling the optical pickup apparatus, a method of detecting optical power, and an optical disk system employing the optical pickup apparatus.
2. Description of Related Art
In recent years, computers have accomplished marked progress in reducing their sizes and enhancing their performance. Optical disk devices are extensively used as storage devices for computers because of their large storage capacities and ease of handling. In keeping with the trend towards downsizing of computers, optical disk devices have achieved a significant reduction in their size.
To successfully reduce the size of an optical disk device, it is most important to make an optical pickup apparatus small-sized. For this reason, various proposals have been made that are considered to be useful for making small-sized optical pickup apparatuses.
For instance, according to the invention disclosed in U.S. Pat. No. 5,712,841 (Willem), a cylindrical unit provided with a diffraction grating and a mirror covers a light source, and a photodetector for detecting returning light from an optical disk is disposed on a side surface of the cylindrical unit. According to another invention disclosed in Japanese Patent Unexamined Publication No. 9-297935, a diffraction grating, a semi-reflecting surface and a transmitting surface are integrally formed with a multifunctional prism.
The xe2x80x9coptical diskxe2x80x9d referred to in the present invention is a generic term of recording media that allow signals to be reproduced therefrom or recorded thereto by using light beams; differences in recording system, including a recording density, the wavelength used for light beams, the combined use with magnetism, are ignored.
The above proposals, however, have not yet provided a satisfactory solution to a configuration or the like required for accurately and efficiently verifying the optical power during recording or a configuration or the like required for accurately disposing and assembling a light source, a photodetector, a multifunctional prism or a cylindrical unit, etc.
No satisfactory solution has been attained even after using light sources or photodetectors having configurations or performance exclusively designed for pickups. Furthermore, even if commercially available various-purpose light sources or photodetectors is used, this has not made it possible to provide a smaller, inexpensive optical pickup apparatuses.
The present invention has been made to solve the aforementioned problems, and it is an object of the invention to provide a small, inexpensive optical pickup apparatus that can be constructed by using a various-purpose luminescent element, and assembled with high accuracy, and is capable of accurately and efficiently detecting the optical power of the luminescent element.
According to the present invention, there is provided an optical pickup apparatus having a various-purpose luminescent element, an integrated optical means for guiding a luminous flux emitted from the luminescent element to an optical disk and for splitting a luminous flux reflected from the optical disk, a light-receiving means for receiving light and converting the received light into an electrical signal, and a coupling means for retaining the positional relationship among the luminescent element, the light-receiving means, and the integrated optical means.
The present invention makes it possible to provide a smaller, inexpensive optical pickup apparatus that can be constructed by using a various-purpose luminescent element, can be assembled with high accuracy, and is capable of accurately and efficiently detecting the optical power of the luminescent element.